linux-toradex.git/include/linux/mount.h, branch tegra-10.9.9

fs: introduce mnt_clone_write

2009-06-12T01:36:02+00:00

This patch speeds up lmbench lat_mmap test by about another 2% after the
first patch.

Before:
 avg = 462.286
 std = 5.46106

After:
 avg = 453.12
 std = 9.58257

(50 runs of each, stddev gives a reasonable confidence)

It does this by introducing mnt_clone_write, which avoids some heavyweight
operations of mnt_want_write if called on a vfsmount which we know already
has a write count; and mnt_want_write_file, which can call mnt_clone_write
if the file is open for write.

After these two patches, mnt_want_write and mnt_drop_write go from 7% on
the profile down to 1.3% (including mnt_clone_write).

[AV: mnt_want_write_file() should take file alone and derive mnt from it;
not only all callers have that form, but that's the only mnt about which
we know that it's already held for write if file is opened for write]

Cc: Dave Hansen 
Signed-off-by: Nick Piggin 
Signed-off-by: Al Viro

fs: mnt_want_write speedup

2009-06-12T01:36:02+00:00

This patch speeds up lmbench lat_mmap test by about 8%. lat_mmap is set up
basically to mmap a 64MB file on tmpfs, fault in its pages, then unmap it.
A microbenchmark yes, but it exercises some important paths in the mm.

Before:
 avg = 501.9
 std = 14.7773

After:
 avg = 462.286
 std = 5.46106

(50 runs of each, stddev gives a reasonable confidence, but there is quite
a bit of variation there still)

It does this by removing the complex per-cpu locking and counter-cache and
replaces it with a percpu counter in struct vfsmount. This makes the code
much simpler, and avoids spinlocks (although the msync is still pretty
costly, unfortunately). It results in about 900 bytes smaller code too. It
does increase the size of a vfsmount, however.

It should also give a speedup on large systems if CPUs are frequently operating
on different mounts (because the existing scheme has to operate on an atomic in
the struct vfsmount when switching between mounts). But I'm most interested in
the single threaded path performance for the moment.

[AV: minor cleanup]

Cc: Dave Hansen 
Signed-off-by: Nick Piggin 
Signed-off-by: Al Viro

Add a strictatime mount option

2009-03-26T17:56:35+00:00

Add support for explicitly requesting full atime updates. This makes it
possible for kernels to default to relatime but still allow userspace to
override it.

Signed-off-by: Matthew Garrett 
Signed-off-by: Linus Torvalds

include/linux/mount.h: remove CVS keyword

2008-10-16T18:21:30+00:00

Remove a CVS keyword that wasn't updated for a long time from a comment.

Signed-off-by: Adrian Bunk 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] pass struct path * to do_add_mount()

2008-08-01T15:25:32+00:00

Signed-off-by: Al Viro

[PATCH] vfs: use kstrdup() and check failing allocation

2008-07-27T00:53:24+00:00

- use kstrdup() instead of kmalloc() + memcpy()
- return NULL if allocating ->mnt_devname failed
- mnt_devname should be const

Signed-off-by: Li Zefan 
Acked-by: Cyrill Gorcunov 
Signed-off-by: Al Viro

Remove "#ifdef KERNEL" checks from unexported headers

2008-04-30T15:29:54+00:00

Remove the "#ifdef __KERNEL__" tests from unexported header files in
linux/include whose entire contents are wrapped in that preprocessor
test.

Signed-off-by: Robert P. J. Day 
Cc: David Woodhouse 
Cc: Sam Ravnborg 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[patch 4/7] vfs: mountinfo: add mount peer group ID

2008-04-23T04:04:51+00:00

Add a unique ID to each peer group using the IDR infrastructure.  The
identifiers are reused after the peer group dissolves.

The IDR structures are protected by holding namepspace_sem for write
while allocating or deallocating IDs.

IDs are allocated when a previously unshared vfsmount becomes the
first member of a peer group.  When a new member is added to an
existing group, the ID is copied from one of the old members.

IDs are freed when the last member of a peer group is unshared.

Setting the MNT_SHARED flag on members of a subtree is done as a
separate step, after all the IDs have been allocated.  This way an
allocation failure can be cleaned up easilty, without affecting the
propagation state.

Based on design sketch by Al Viro.

Signed-off-by: Miklos Szeredi 
Signed-off-by: Al Viro

[patch 3/7] vfs: mountinfo: add mount ID

2008-04-23T04:04:45+00:00

Add a unique ID to each vfsmount using the IDR infrastructure.  The
identifiers are reused after the vfsmount is freed.

Signed-off-by: Miklos Szeredi 
Signed-off-by: Al Viro

[PATCH] move a bunch of declarations to fs/internal.h

2008-04-22T03:11:01+00:00

Signed-off-by: Al Viro